Production of crimped artificial filaments, fibers, and the like



Dec. 6, 1938.

D. FINLAYSON ET AL PRODUCTION OF CRIMPED ARTIFICIAL FILAMENTS, FIBERS, AND THE LIKE Original Filed June 4,1937

Patented Dec. 6, 1938 UNITED STATES PATENT, OFFlCE PRODUCTION OF cnnurnn ARTIFICIAL FILAMENTS, FIBERS, AND THE LIKE Donald Finlayson and Richard Gilbert Perry,

Spondon, near Derby, England,

Celanese Corporation tion of Delaware Original application assignors to of America, a corpora,-

June 4, 1937. Serial No.;

146,378. Divided and this application July 28,

1938, Serial'NoI so, 1936 1 221,740. In Great Britain July 4 Claims. (01. 28-1) The present invention is a divisional of U. S.

application S. No." 146,378 filed 4th June 1937,

' terials such as cotton and wool in that the artificial filaments are relatively smooth and do not contain the minute crinkles or crimps which occur naturally in cotton and wool fibers and which are largely responsible for the characteristic handle, fullness and elasticity of such materials. Moreover, the naturally-occurring crinkles or crimps in cotton and wool fibers assist in the interlocking of the fibers in spinning operations and thus promote the coherence which results. in the good spinning properties of the fibers. Thus, when spinning staple fiber produced from artificial filaments in machinery of the type used in the production of cotton" or wool yarns, the smoothness of the artificial material allows of excessive slip between the fibers, with the result that a sufficient degree of coherence is difiicult to obtain and the s innin rocess is rendere enerp g p d g hate and cellulose butyrate, and cellulose ethers,

ally m'ore difiicult.

It is an object of the invention to improve the handle or feel and spinning properties of artificial filaments of cellulose acetate or other organic derivatives of cellulose and generally to impart to such filaments a crimped structure akin to that of cotton or wool fibers.

According to the invention, artificial filaments of cellulose acetate or other organic derivatives of cellulose are laid across each other in a crlsscross manner, and while they are so disposed are subjected to mechanical pressure and a softening medium comprising a substance having a solvent action on the cellulose to soften the filaments while the mechanical pressure is maintained on the filaments, the filaments then being dried and set by passing'a drying medium therethrough while the mechanical pressure is maintained. The pressure forces filaments minute waves or crimps at the pointsat which the filaments cross each other with the result'that the filaments assume a generally crimped structure. The'treated filaments are allowed to set and dry in the compressed state', and on completion of the process are found to have a full, springy handle or feel and an enhanced covering power,

derivative is applied Any suitable substance having a solvent or fartial solvent or softening action on the material of the filaments maybe employed to soften the filaments. 7 Thus, for the treatment of cellulose acetate filaments there may be used a solvent such as acetone in aqueous solution.

Continuous or long lengths of filaments-treated according to the invention may be parallelized and converted into relatively shortstaple lengths (e. g. by cutting) for spinning on cotton or wool machinery in the manner of cotton or wool fibers, or, if desired, untreated continuous or long lengths offilaments may first be converted into relatively short staple lengths and the staple lengths'may then be treated'in the manner described above, i. e. by softening and pressing a 'criss-cross mass of the staple lengths.

Yarns and fabrics containing the filaments treated according to the invention assume characteristics of the component filaments in that they have a full springy handle or feel and have enhanced covering power, 7

Organic derivatives of cellulose of which the filaments may be composed other than the cellulose acetate already mentioned are cellulose esters, such as cellulose formate, cellulose propiosuch as' ethyl, methyl, butyl, propyl and'benzyl cellulose. I

By way of example a method of crimping artificial filaments according to the invention will -now be described in greater detailwith reference to the accompanying diagrammatic drawing which is a part cross-sectional elevation of' apparatus suitable for ments.

Continuous artificial filaments of cellulose ace-V tate are converted into relatively short staple lengths appropriate to the type of fibers to be produced (e. g. one to two or more inches if fibers resembling cotton are to be produced, and three to seven or more inches if fibers resembling wool are to be produced) and the short lengths are opened and loosened by s'cutching.

The loose fibers are then arranged in crisscross layers or the treatment of the fila-.

filled. A loose perforated plate 3 shaped so as to portion 6 of the plate 3. The raised portion 6 is formed with a suitable dimple for the reception of the rounded end of the screw.

The plate 3 is pressed downwardly by the screw 4% until the fibers are forced into intimate contact with each other, a pressure of about lb. per square inch being suificient to induce minute waves or crimps in the filaments at the points at which they cross each other. When such pressure is reached, the rotation of the screw is stopped and a circular lid 1 formed at its centre with a threaded boss (5 and engaged and carried by the screw is rotated about the screw until the edge of the lid comes tightly into contact with a packing ring 9 disposed around the top of the chamber I.

On the chamber i. being thus charged with compressed crimped fibers of cellulose acetate of, say, 2 inches in length and closed by the lid 7,

the fibers may be soaked while in the chamber by connecting a suitable supply of acetone in a 30% by volume solution in water to the chamber by a pipe I ll controlled by a valve H and the drain l2 controlled by a valve l3, and pumping or otherwise circulating the acetone and water through the chamber for the requisite period prior to dryingl In this manner the compressed fibers are softened in the .crimped condition. As a result the structure of the fibers is modified and conformed to the crimped condition, the fibers being found to have a characteristic curl or wave. 7

If desired the'fibers may be softened by being soaked for 10 minutes in a solution of acetone and water and then placed in the chamber l and subjected to pressure in the manner described above.

When the compressed fibers have been subjected to the action of the acetone and water, the

valve I I is closed and a drying current of hot air is passed into the chamber from a pipe l4 controlled by a valve IS. The hot air is forced through the softened fibers and escapes from the chamber through the drain l2, the flow of air.

being maintained until the fibers are dried and set in their crimped condition.

After drying and setting the lid 1 is unscrewed and the mechanical pressure on the fibers is released, the now crimped and set fibers being removed from the chamber in readiness for spinning. The chamber may then be used for crimpmg a further supply of material. b

Artificial fibers crimped according to the in-- vention may be spun into yarn and woven into fabric either alone or mixed with wool and/or cotton or other textile fibers; When mixed with other fibers pleasing cross-dyed effects may be obtained by subjecting the yarn or fabric to the action of a dyestufE having afiinity for one class of fiber only. The remaining fibers may be left undyed or may be dyed difierent colours.

Having described our invention, what We desire to secure by Letters Patent is:.

1. Process for the production of crimped artificial filaments, which process comprises laying filaments of cellulose acetate or other organic derivative of cellulose across each other in a criss-cross manner, and while they are so disposed subjecting .the filaments to mechanical pressure, applying a softening medium comprising a substance having a solvent action on the cellulose derivative to soften the filaments while the mechanical pressure is maintained, and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

2. Process for the production of crimped artificial filaments, which process comprises laying filaments of cellulose acetate or other organic derivative of cellulose across eachother in a criss-cross manner, and while they are so disposed subjecting the filaments to mechanical pressure, applying an aqueous solution of solvent for the cellulose derivative to soften the filaments while the mechanical pressure is maintained, and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

3. Process for the production of crimped artificial filaments, which process comprises laying filaments of cellulose acetate or other organic derivative of cellulose across each other in a" criss-cross manner, and while they are so disposed subjecting the filaments to mechanical pressure, applying an aqueous solution of acetone to "soften the filaments while the mechanical pressure is maintained," and then drying and setting the filaments by passing a drying medium therethrough while the mechanical pressure is maintained.

4. Process for the production of crimped artificial filaments, which process comprises laying filaments of cellulose acetate or other organic derivative of cellulose across each other in a. 

